JPH10105013A - Image forming device - Google Patents

Abstract

[PROBLEMS] To efficiently separate high-quality toner from residual toner collected from a photoreceptor after image transfer by a cleaning device so that the toner can be reused in a developing device. SOLUTION: On a side surface of a cleaning device 23, a guide member 23 having a plurality of openings 233A opened in series on a bottom surface.
3 and an opening 233 close to the cleaning device 23.
A is covered with a mesh member 233B, and an opening 24A of the toner conveying pipe 24 connected to the developing device 14 is opened on the upper surface immediately below the mesh member 233B, while the opening 2 on the end side of the guide member 233 is opened.
A waste toner container 25 is disposed immediately below the toner collecting screw 233. Only the normal toner from the residual toner conveyed by the toner collecting screw 232 is filtered by the mesh member 233B, and is passed through the toner conveying pipe 24 to the developing device. 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic recording system in which an electrostatic latent image formed on a peripheral surface of an image forming body is developed by a developing means having a built-in toner into a toner image, which is transferred to a transfer material and recorded. Related to an image forming apparatus.

[0002]

2. Description of the Related Art After a toner image formed on an image forming body is transferred to a transfer material, the transfer material holding the toner image is fixed and discharged out of the apparatus, but remains on the image forming body. The toner image is removed by the cleaning unit and collected as residual toner in preparation for the formation of a subsequent electrostatic latent image. The collected residual toner may be collected and discarded. Usually, the residual toner is directly sent to the developing unit via a toner conveying unit provided between the cleaning unit and the developing unit, and is reused as a developer. .

[0003]

However, in general, the residual toner is often partially coagulated or mixed with paper dust or foreign matter. Therefore, the toner image developed by reuse is often streaked. In some cases, the image quality may be degraded due to occurrence of chipping.

[0004] The present invention has solved and improved the above points,
An object of the present invention is to provide an image forming apparatus capable of reusing only high-quality toner as a developer by removing coagulated matter, paper powder, and the like from residual toner.

[0005]

An object of the present invention is to transfer a toner image formed on an image forming body onto a transfer material, and then collect residual toner on the image forming body by a cleaning means and reuse it in a developing means. In the image forming apparatus, the cleaning unit conveys the collected residual toner to the mesh member via the guide member, uses the toner component filtered by the mesh member again in the developing unit, and discards the residual component not filtered. This is achieved by an image forming apparatus having the above configuration.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The sectional structure and function of an image forming apparatus according to the present invention will be described with reference to FIG.

In FIG. 1, reference numeral 10 denotes a photosensitive drum serving as an image carrier, for example, an OPC photosensitive member coated on the drum, which is grounded and driven to rotate clockwise. Reference numeral 12 denotes a scorotron charger, which is a photosensitive drum by corona discharge using a grid maintained at a predetermined potential and a corona discharge wire.
A negative uniform charge is applied to the 10 circumferential surfaces to give a potential of _VH . Prior to charging by the scorotron charger 12, in order to remove the history of the photoconductor up to the previous print, exposure by the PCL 11 using a light emitting diode or the like is performed to eliminate the charge on the peripheral surface of the photoconductor.

After the photosensitive drum 10 is uniformly charged, the laser writing device 13 performs image exposure based on the image signal. In this image exposure, an image signal input from a computer or an image reading device is processed by an image signal processing unit and then input to a laser writing device 13 to form a latent image on the photosensitive drum 10.

The laser writing device 13 is a rotating polygon mirror 13 which rotates using a laser diode (not shown) as a light source.
1, a plurality of reflecting mirrors M1 and M
The main scanning is performed by bending the optical path by M2 and M3, and a sub-scan is performed by the rotation of the photosensitive drum 10 to form a latent image. In the present embodiment performs exposure on the basis of the image signal to the image portion is an image forming area on the image bearing member, a reversal latent image absolute value of the potential at the exposed portion becomes lower V _L than V _H Form.

On the peripheral surface of the photoreceptor drum 10, a developing container 14 for storing a developer composed of a black toner and a magnetic carrier, which is negatively charged, is provided. The latent image is composed of the toner and the carrier. Developing sleeve 1 for holding developer
The image is developed by rotation of 41.

The developer is attracted to the peripheral surface of the sleeve by the attraction force of the magnet body contained in the developing sleeve 141, and the layer thickness regulated by the layer thickness regulating member is transported to the developing area.

In the developing area, a developing sleeve 141 is provided.
The developer attached to the peripheral surface slides on the peripheral surface of the photosensitive drum 10, and a DC voltage _VDC is applied between the developing sleeve 141 and the photosensitive drum 10. DC voltage V
_The toner has the same polarity (negative) as _DC , so the toner is
Not adhere to a portion of the high V _H absolute value of the potential from the DC voltage V _DC of the above, V _DC in absolute value portion of the lower V _L potential
And the amount of toner corresponding to the potential difference between the toner and the toner adheres, and visualization (reversal development) is performed.

At the same time, the recording paper P is conveyed by the rotation of the paper feed roller 151 from the paper feed cassette 15, and
The paper is fed to the timing roller 17 via the conveyance guide 16.

Next, the recording paper P is fed to the transfer area by the rotation of the timing roller 17 in synchronization with the toner image on the photosensitive drum 10, and the toner on the photosensitive drum 10 is discharged by the discharge of the transfer unit 18. The image is transferred to recording paper P.

The recording paper P on which the toner image has been transferred is separated by a separator 1
9, the toner is separated from the drum peripheral surface by the discharge of No. 9, and is conveyed to the fixing device 21 via the conveying belt 20, where the toner is welded by the nip heating between the heat roller 210A and the pressure roller 210B, and the discharge rollers 211 and 212 are discharged. Is discharged to the tray 22 outside the apparatus.

On the other hand, the photosensitive drum 10 from which the recording paper P is separated
Is removed by the pressing action of the blade 231 provided in the cleaning device 23 to remove and clean the residual toner after the transfer, to return to a state where the next toner image can be formed, and the residual toner removed by the cleaning device 23 The toner falls to the bottom and is transported from the bottom toner recovery screw 232 to the developing device 14 via toner transport means (not shown), and is reused as a developer.

FIG. 2 shows an embodiment of a toner conveying path from the cleaning device 23 to the developing device 14, in which the cleaning device 23 has a U-shaped cross section at the bottom of the side surface.
A guide member 233 which is shaped like a letter is integrally protruded, and the toner collecting screw 232 is extended to the closed end so that the residual toner collected in the cleaning device 23 can be conveyed. I have.

The guide member 233 has a pair of openings 233A opened in series on the bottom surface near the end bottom surface of the terminal end in the transport direction.
Only the opening 33A is covered with the mesh member 233B.

The cleaning device 23 and the developing device 14
A toner conveying pipe 24 containing a toner conveying screw 241 is provided between the toner conveying screws 241.
Is disposed so as to be substantially orthogonal to the toner collection screw 232, so that the opening 24 </ b> A provided on the upper surface of one end of the toner conveying pipe 24 is
An opening 24B at the other end of the toner conveying pipe 24 is opened above the toner receiving port 14A provided in the developing device 14. The toner transport screw 241 is rotated by the power of a driving member (not shown), and has a function of transporting the collected toner from the cleaning device 23 to the developing device 14.

After the transfer to the recording paper P, the so-called residual toner remaining on the photosensitive drum 10 is removed by the blade 231 of the cleaning device 23 and the cleaning device 2
The toner that has fallen to the bottom of the guide member 3 is conveyed toward the end of the guide member 233 by the rotation of the toner collection screw 232.

When the residual toner conveyed to the vicinity of the end of the guide member 233 passes through the upper surface of the mesh member 233B, only high-quality toner having a small particle size, that is, other than paper powder and agglomerated toner is filtered and dropped. Then, the toner conveying screw 24 is accommodated in the toner conveying pipe 24 through the opening 24A.
Due to the rotation of 41, it moves inside the toner transport pipe 24, falls through the opening 24B into the toner receiving port 14A, enters the inside of the developing device 14, and reciprocates by a pair of stirring screws. The toner is mixed with the carrier and used for reuse.

On the other hand, foreign matter having a large particle size, such as a toner lump or paper powder, which is not filtered by the mesh member 233B, passes through the opening 24B, is conveyed to the end of the guide member 233 by the toner collecting screw 232, and Opening 23
The toner drops from 3A, is stored in the waste toner container 25, and is discarded.

The mesh member 233B has an appropriate mesh roughness in the range of 20 to 80 so that the mesh can pass through the carrier in the case of using a toner in a normal state or a two-component developer. It is practically preferable to set about 5 to 30% of the collected residual toner as waste toner. When the mesh of the mesh member 233B is rougher than the above range, the above foreign matter is also collected, and when the mesh is finer than the above range, even high-quality collected toner is discarded.

As shown in the embodiment of FIG. 3, only one opening 233A is opened at the end of the guide member 233, and the waste toner container 25 is disposed immediately below the opening 233A. The mesh member 2 is disposed inside the waste toner container 25.
33B, the vibrating net member 233B is filtered to filter the vibrating net member 233B, and the dropped toner is transferred to the toner transport tube 24, and the unfilterable toner mass and other residue are transferred to the waste toner container 25. They can be separated and reused or disposed of.

That is, the mesh member 233B is intermittently rotated about the axis H to a position shown by a dashed line by the pushing-up operation of the cam C integrated with the toner conveying screw 241 and then solid line by its own weight. The operation of returning to the position indicated by the symbol can be repeated, and the vibrating action promotes the sorting effect of the net-like member 233B, so that the toner having a small particle size falls into the toner transport pipe 24. At the same time, the toner mass or the like having a large particle size can be dropped and accommodated in the waste toner container 25 along the inclined net-like member 233B by jumping up foreign matters.

[0026]

According to the first aspect of the present invention, only high-quality toner components that can withstand reuse can be supplied from the residual toner collected by the cleaning unit to the developing unit, and a high-quality image can always be formed. , And further claim 2,
According to the third and fourth aspects, it is possible to appropriately and easily separate the toner component and the residue from the residual toner, and to simplify the configuration of the toner conveying means. Further, according to the fifth aspect, the toner component recovery efficiency is enhanced, and According to No. 6, when the two-component developer is used, the reuse of the carrier together with the toner component is realized.

[Brief description of the drawings]

FIG. 1 is a cross-sectional configuration diagram of an image forming apparatus of the present invention.

FIG. 2 is a main part view of an apparatus showing a collecting means (part 1) of residual toner.

FIG. 3 is a main part view of an apparatus showing a residual toner collecting means (part 2).

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 photoconductor drum 12 scorotron charger 13 laser writing device 14 developing device 14A toner receiving port 15 paper feed cassette 17 timing roller 18 transfer device 23 cleaning device 24 toner transport tube 24A, 24B, 233A opening 25 waste toner container 232 toner recovery Screw 233 Guide member 233B Mesh member 241 Toner transport screw

Claims (6)

[Claims] An image forming apparatus for transferring a toner image formed on the image forming member onto a transfer material, collecting remaining toner on the image forming member by a cleaning unit, and reusing the remaining toner in a developing unit. The means conveys the collected residual toner to a mesh member via a guide member, reuses the toner component filtered by the mesh member in the developing means, and discards the unfiltered residual component. Image forming device. 2. The image forming apparatus according to claim 1, wherein a toner collecting screw provided in said cleaning means and a toner conveying screw provided in said developing means are provided at right angles. 3. The image forming apparatus according to claim 1, wherein the mesh member is provided near an end of the guide member. 4. The image forming apparatus according to claim 1, wherein the mesh member is provided on a bottom surface of the guide member. 5. The image forming apparatus according to claim 1, wherein a residual component to be discarded accounts for 5 to 30% of the collected residual toner. 6. The image forming apparatus according to claim 1, wherein the mesh member has a mesh of 20 to 80 mesh.